/Engine/Plugins/Developer/Concert/ConcertMain/Source/ConcertClient/Public/IConcertClient.h
It is required that the task return Pending while it is in-progress, and Success when it has finished successfully. Any other status is treated as an error state, and GetError will be called.
[EConcertResponseCode](API\Plugins\ConcertTransport\EConcertResponseCode) GetStatus() const